A/C help needed

Is there a writeup somewhere on how to plumb-in and wire-in the A/C in a 944 Turbo/LS1 swap? I've been searching the site but have had no luck.

Thanks!

When you searched did you use advanced search and the google button? If you didn't it should get you more posts.
There seem to be several ways to get the job done. You can have the Porsche electronics or the LS1 PCM control the AC and fans. Several members have A/C I am sure they will be glad to help out.

Thanks Tim, I was not aware of the advanced search/google option. I'm finding a lot of stuff now.

Tim, thanks, I understand the hose routing now.

Also, you referenced what turned out to be the Porsche A/C compressor power/on/off connection/connector here: [You must be registered and logged in to see this link.]

I'm having a bear of a time locating it on my car. Can you describe where it's located? I can't tell from the pic that Admin uploaded where his pic is taken from. Above? Below?

I guess if I had taken the old engine out, I would have a better idea where to look...

That connector pigtails off of the wire harness going down the drivers side frame rail to the headlights. If it is still there it should just be dangling somewhere between the wheel well and the front of the car.

Do you know how the fans are controlled on your car? That would help determine how you wire up the A/C.

Thanks Tim, I'll look for the A/C connector in the AM when it's light out. The fans continue to run for a minute or so after I shut the engine off, so I assume they are running off the Porsche electronics.

If they are running off of the Porsche system then you could run the power wire off of the pigtail to the GM compressor and ground it. Do you still have any of the Porsche original lines or condenser?

Tim, the condensor looks to be OEM and it looks like the short OEM line that went from it to the OEM compressor is still in place. I think that line would need to be replaced with a longer line with the correct GM fitting in order to reach and mate with the GM compressor. The large vacuum line from the firewall to the compressor is new and in place except it also needs a GM fitting for the compressor.

Thanks Tim, I just found the A/C pigtail. Making progress!

Andy

PS: The hydroboost addition is on the back burner now, I've gotten completely used to the manual brakes and they work fine.

The Porsche compressor is in place? On the drivers side? That would be odd. If you have compressor on the passenger side that would be the GM factory location.
Run the pigtail over to the GM compressor and extend the lines with the appropriate fittings to hook up to the GM compressor and you should be in buisness. Basically, the Porsche electronics are just running a compressor so it shouldn't matter what kind it is. Or so I have been told. My plans are to have the LS1 PCM run the fans and A/C off of a stand alone fuse box.

No the Porsche compressor is not in place, it's pigtail is. I'll tap the GM compressor (on the pass side) into that pigtail and extend the hoses as you said.

Do you have the factory switch in the hose just before the dryer?

If you use a GM compressor (Its a variable pressure unit) with the Porsche Dryer/Switch then you have to remove the valve from the compressor, cap the end and refit. It then behaves like a fixed pressure compressor.

If the Porsche system is controlling the fans and A/C the fans kick on when the A/C is triggered. What if the Porsche system controls the A/C but the GM PCM controls the fans? The PCM won't see the A/C to turn on the fans or to idle up. Would this be a problem? The fans would still be triggered at the target temp. This may turn into a proper A/C thread.

Thanks guys, well, I assume it's the 944 drier, not sure how to identify it for sure. It has two gizmos in the manifold/hose just before the drier, both pigtailed to the harness. Is one a sensor and the other a switch?

Anyway, assuming it is the 944 drier, where is the valve in the compressor that needs to be capped and how do I cap it?

If I used a GM drier instead, I assume I would then not have to cap the compressor valve? Is there any benefit to a variable pressure compressor vs. a fixed pressure compressor?

Lastly, I need to source a manifold for the compressor, is the stock 2002 Camaro manifold OK? (My engine is from a 2002 Camaro.) I assume the tubes on the compressor manifold can be bent if necessary, to accommodate the A/C lines coming in from non-stock directions? My hoses look like they'll come in from underneath the compressor from the driver's side front. Or is the manifold from a different engine better suited to our application?

Just when I thought I had it all figured out!....

The driers are generic, the switches/sensors sound like the factory system. I don't know anything about modifications to the compressor, that is interesting. I would guess the Porsche compressor wasn't variable so the GM compressor needs to be modified to make it constant pressure. There are different manifolds off of the compressor that can be purchased to direct the hoses in better directions. Doc's blocks and vintage air have a selection.

Here are two pics:

The Valve I removed from the compressor and the location in the compressor where the valve fits.
Valve is retained by a circlip. Note that the small end of the valve has been closed with a touch of weld.

[You must be registered and logged in to see this image.]

PM me for an article on RCV valves. Can't post it here.

Here is an article explaining how to do it with pictures
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Thanks, that's the article I have.

Thanks guys, huge amount of info here! Here's what looks like a decent adaptor/manifold to use on the GM compressor:

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I suppose some of those 45 or 90 degree fittings would help too. I'll also check out Doc's Blocks and Vintage Air.

edit: Doc's Blocks has an adaptor/manifold too: [You must be registered and logged in to see this link.]

Vintage Air has piles of good stuff too although it's hard for me to see which fittings, etc., would work the best w/o actually holding them in my hand.

Both of my lines to the compressor are coming from their original locations on the driver's side. I suppose they'll go underneath the front of the engine over to the compressor on the passenger side. It might be a tight-ish bend up to get to the compressor fittings.

Anyone know how tight a bend you can/should put in an A/C line?

I have seen one that had the compressor fittings going down and under the compressor. That would be ideal.

Any one aware of crimp style fittings that fit the 944 bulkhead AC points.
I have looked everywhere and have come to the conclusion that I have to cut and
weld the old pipes to new fittings.

Anthro, I agree, do you remember where you saw that? Love to see a pic.

Anyway, Vintage has some bendable A/C pipes that could be used from the adaptor block down and under the compressor to the hose fittings, though that would add an additional connection (pipe to hose fitting connection) that could leak, I suppose.

What would be nice would be, say, 6"-10" bendable hose fittings. Surely someone makes something like that? Probably it wouldn't be too expensive to have some custom fittings fabbed up.

Mike, everything I have read says that the only solution is to cut and weld, as you say.